[PATCH v3 4/8] thermal: amlogic: Add support for secure monitor calibration readout

Ronald Claveau
2026-04-21T07:20:30Z

Some SoCs (e.g. T7) expose thermal calibration data through the secure
monitor rather than a directly accessible eFuse register. Add a use_sm
flag to amlogic_thermal_data to select this path, and retrieve the
firmware handle and tsensor_id from the "amlogic,secure-monitor" DT
phandle with one fixed argument.

Also introduce the amlogic,t7-thermal compatible using this new path.

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
drivers/thermal/amlogic_thermal.c | 58 +++++++++++++++++++++++++++++++++++----
1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/amlogic_thermal.c b/drivers/thermal/amlogic_thermal.c
index 5448d772db12a..11e3948cc0669 100644
--- a/drivers/thermal/amlogic_thermal.c
+++ b/drivers/thermal/amlogic_thermal.c
@@ -25,6 +25,7 @@
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>
+#include <linux/firmware/meson/meson_sm.h>

#include "thermal_hwmon.h"

@@ -84,12 +85,14 @@ struct amlogic_thermal_soc_calib_data {
* @u_efuse_off: register offset to read fused calibration value
* @calibration_parameters: calibration parameters structure pointer
* @regmap_config: regmap config for the device
+ * @use_sm: read data from secure monitor instead of efuse
* This structure is required for configuration of amlogic thermal driver.
*/
struct amlogic_thermal_data {
int u_efuse_off;
const struct amlogic_thermal_soc_calib_data *calibration_parameters;
const struct regmap_config *regmap_config;
+ bool use_sm;
};

struct amlogic_thermal {
@@ -100,6 +103,8 @@ struct amlogic_thermal {
struct clk *clk;
struct thermal_zone_device *tzd;
u32 trim_info;
+ struct meson_sm_firmware *sm_fw;
+ u32 tsensor_id;
};

/*
@@ -138,6 +143,12 @@ static int amlogic_thermal_initialize(struct amlogic_thermal *pdata)
int ret = 0;
int ver;

+ if (pdata->data->use_sm) {
+ return meson_sm_get_thermal_calib(pdata->sm_fw,
+ &pdata->trim_info,
+ pdata->tsensor_id);
+ }
+
regmap_read(pdata->sec_ao_map, pdata->data->u_efuse_off,
&pdata->trim_info);

@@ -226,6 +237,12 @@ static const struct amlogic_thermal_data amlogic_thermal_a1_cpu_param = {
.regmap_config = &amlogic_thermal_regmap_config_g12a,
};

+static const struct amlogic_thermal_data amlogic_thermal_t7_param = {
+ .use_sm = true,
+ .calibration_parameters = &amlogic_thermal_g12a,
+ .regmap_config = &amlogic_thermal_regmap_config_g12a,
+};
+
static const struct of_device_id of_amlogic_thermal_match[] = {
{
.compatible = "amlogic,g12a-ddr-thermal",
@@ -239,6 +256,10 @@ static const struct of_device_id of_amlogic_thermal_match[] = {
.compatible = "amlogic,a1-cpu-thermal",
.data = &amlogic_thermal_a1_cpu_param,
},
+ {
+ .compatible = "amlogic,t7-thermal",
+ .data = &amlogic_thermal_t7_param,
+ },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, of_amlogic_thermal_match);
@@ -271,11 +292,38 @@ static int amlogic_thermal_probe(struct platform_device *pdev)
if (IS_ERR(pdata->clk))
return dev_err_probe(dev, PTR_ERR(pdata->clk), "failed to get clock\n");

- pdata->sec_ao_map = syscon_regmap_lookup_by_phandle
- (pdev->dev.of_node, "amlogic,ao-secure");
- if (IS_ERR(pdata->sec_ao_map)) {
- dev_err(dev, "syscon regmap lookup failed.\n");
- return PTR_ERR(pdata->sec_ao_map);
+ if (pdata->data->use_sm) {
+ struct device_node *sm_np;
+ struct of_phandle_args ph_args;
+
+ ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
+ "amlogic,secure-monitor",
+ 1, 0, &ph_args);
+ if (ret)
+ return ret;
+
+ sm_np = ph_args.np;
+ if (!sm_np) {
+ dev_err(dev,
+ "Failed to parse secure monitor phandle\n");
+ return -ENODEV;
+ }
+
+ pdata->sm_fw = meson_sm_get(sm_np);
+ of_node_put(sm_np);
+ if (!pdata->sm_fw) {
+ dev_err(dev, "Failed to get secure monitor firmware\n");
+ return -EPROBE_DEFER;
+ }
+
+ pdata->tsensor_id = ph_args.args[0];
+ } else {
+ pdata->sec_ao_map = syscon_regmap_lookup_by_phandle
+ (pdev->dev.of_node, "amlogic,ao-secure");
+ if (IS_ERR(pdata->sec_ao_map)) {
+ dev_err(dev, "syscon regmap lookup failed.\n");
+ return PTR_ERR(pdata->sec_ao_map);
+ }
}

pdata->tzd = devm_thermal_of_zone_register(&pdev->dev,

--
2.49.0